I have a 2012 KIA Sedona LX that we tow a small travel trailer with for camping trips. I have always wondered what my transmission temperature was doing on the hills. I did install an extra cooler in front of the radiator. I recently bought a UltraGauge MX as they advertised it as able to read transmission fluid temperature if you were able to program their Mgauges. I am posting this here just in case anybody else wants to do this as well.
Here are the codes needed to make the UltraGauge read the transmission fluid temperature in my 6-spd automatic.
TDATA: 07E121A0
TCTRL: 92
RCTRL: 10
RPOS 1808
MATCH: 220000
X:0009
/:0005
+:FFD8
Out Format: 00
Ave: 00

I can not vouch for anything other than 2016 KIA Sedona 3.5L 6-spd Auto.
My guess is that it should work for the Hyundai as well.